Two opposite problems that look similar at a glance
A driveway that's cracked, a sidewalk panel that's stepped up at a joint, a slab that's visibly uneven: the surface symptom often looks the same whether the ground pushed the concrete up or let it sink down. But heave and settlement are opposite mechanisms with different fixes, and in Colorado Springs there's a third possibility, freeze-related surface movement, layered on top. Getting the diagnosis right matters more here than in most markets, because the honest answer depends on where you live, not just what you see.
Settlement: the ground gave way underneath
Settlement is downward movement: the subgrade under part of a slab compresses, consolidates, or washes out, and that section of concrete drops. It shows up as a slab or panel that's lower than its neighbors, often with a crack running along the low edge and a step down at the joint. Common causes are poor original compaction, erosion from water running under the slab, or a void that opened up underneath over time.
Settlement is the target case for slabjacking or polyjacking. Both methods lift a settled panel back toward level by filling the void underneath, either with a cement slurry (slabjacking) or expanding polyurethane foam (polyjacking). Neither method helps if the slab is cracked through or the settlement is severe enough that the concrete itself has failed. At that point, replacement is the right call.
Heave: the ground pushed the concrete up
Heave is the opposite: something underneath the slab expanded and pushed it upward, unevenly. It shows up as a panel that's higher than its neighbors, a faulted joint with the offset going the other direction from settlement, or, on a longer run like a driveway, a rolling, uneven "roller-coaster" profile where multiple sections have lifted by different amounts.
In most expansive-clay markets, heave comes from a uniform blanket of shrink-swell clay at the surface. Colorado Springs is not that market, and claiming it is would be the wrong local story.
Why heave here is a two-layer, address-dependent story
Measured soil data across the Colorado Springs residential grid shows most surface soil is arkosic sand, low-shrink material shed off the granitic Rampart Range, with a low Liquid-Extension-Percentage (LEP) around 1.3 to 1.5 and clay content generally 5 to 15%. Sand like that doesn't heave meaningfully with moisture change. If that were the whole story, Colorado Springs wouldn't have a heave problem at all.
But it isn't the whole story. The Colorado Geological Survey has specifically mapped "heaving bedrock hazards" in the western part of the City of Colorado Springs: steeply-dipping, expansive claystone bedrock in the Pierre Shale and other Upper Cretaceous formations, sitting at shallow depth in that area. The agency's own language is direct: engineered facilities there "may be subjected to destructive, differential ground heave if expansive layers of bedrock are encountered at shallow depth," and describes a "'roller-coaster' road" as "the result of uneven expansion and heaving of steeply dipping bedrock layers." Where that bedrock sits shallow, or where a soil survey turns up one of the scattered smectitic clay pockets in the county (one measured location in west-central Colorado Springs came back with an LEP of 7.5 and clay content up to 47.5%, a true expansive clay), the heave hazard is real and can be severe. The Colorado Geological Survey attributes to expansive ground materials generally: up to 20% volume expansion, up to 30,000 pounds per square foot of force, and specifically "cracked driveways, sidewalks and basement floors" as the resulting damage.
Stated plainly: this hazard is real, well documented, and can be severe. But it is bedrock-controlled and patchy, not a uniform clay blanket under the whole metro. The state geological survey's own mapping documentation says as much: the heaving-bedrock map "does not show areas where thick, surficial-soil deposits may cover the bedrock, significantly reducing the heaving potential," and doesn't distinguish high, moderate, or low swell potential within the area it does map. A driveway on deep sandy soil away from the mapped western-city bedrock zone is unlikely to see meaningful clay- or bedrock-driven heave; a driveway sitting on shallow bedrock or a Heldt-type clay pocket can see real, destructive movement. The correct answer for a specific address is a soil and bedrock check for that parcel, not an assumption that Colorado Springs either "has expansive clay" or "doesn't."
The third wrinkle: freeze-related surface movement
Because Colorado Springs also runs roughly 160 days a year with a low temperature at or below 32°F (more than double a market like Oklahoma City), some upward or uneven concrete movement here can be freeze-related rather than clay- or bedrock-driven: repeated freeze-thaw cycling at the surface, or frost action in saturated soil right under a slab, can contribute to unevenness distinct from the deep bedrock-heave mechanism above. The freeze-thaw driver more commonly shows up as surface scaling, spalling, or D-cracking rather than a faulted joint or a lifted panel. See why concrete fails in Colorado Springs for how to separate the two by what the crack looks like.
Reading the difference
| Symptom | Likely cause |
|---|---|
| Panel is lower than neighbors, crack along the low edge | Settlement |
| Panel is higher than neighbors, or a rolling/uneven driveway profile | Heave; check whether the address sits near mapped bedrock or a known clay pocket |
| Surface flaking or scaling, no clear offset | Freeze-thaw surface distress, not heave or settlement |
| Random, map-like cracking with no offset | Ordinary drying-shrinkage (cosmetic) |
What each diagnosis means for the fix
- Settlement: slabjacking or polyjacking lifts a sound, settled slab back toward level; tear-out and replacement if the slab itself has failed.
- Heave: the fix depends on severity and cause. Address-level correction typically starts with moisture management (drainage away from the slab, consistent watering rather than wet-dry swings where clay is present) and can extend to a void-form or structurally designed slab, or piers to a stable bearing layer, on lots where the bedrock or clay hazard is confirmed. A repair or replacement that ignores an active heave source will move again.
- Freeze-thaw surface distress: typically a resurfacing or sealing fix rather than a structural one, paired with correct air-entrainment on any new pour.
Questions people ask
Does my whole neighborhood have expansive clay? Not necessarily. Most residential surface soil around Colorado Springs is low-shrink sand; the real expansive hazard is concentrated in mapped western-city bedrock and scattered clay pockets elsewhere in the county. The only way to know for a specific address is a soil and bedrock check for that parcel.
My driveway has a rolling, uneven profile but no single obvious crack — what is that? That "roller-coaster" pattern is the signature the Colorado Geological Survey specifically describes for heaving bedrock: uneven expansion of steeply dipping bedrock layers pushing sections up by different amounts. Worth checking whether the property sits within the mapped western-city hazard area.
If a contractor tells me it's "just the clay," should I take that at face value? Ask what they checked. Given how patchy this hazard is here (most of the metro sits on low-shrink sand), "it's the clay" without a soil or bedrock reference for the specific address is a generic answer applied to a market where the real story is more specific than that.
Area covered
Colorado Springs, CO and El Paso County.